To investigate lymphocyte ATPase activity in patients with solid tumors and lymphoproliferative disorders and determine the conditions when the enzyme activity is elevated. To study the effect of radiation, chemotherapy and immunotherapy on lymphocyte metabolism. To determine the cellular nucleotide pools of lymphocytes from cancer patients and control groups. To investigate the relationship between lymphocyte ATPase activity and other tri-, di-, mono-nucleotides as well as other phosphates.